No, usually never three days on dreams. I have
had some that are about two weeks. I can never
be sure until something sort of trips a trigger
in my mind. Last week I had a seemingly unrelated
dream, but upon awakening for some reason the
island of Madagascar came to mind. This is why
I expanded this one from Indonesia to possibly
somewhere in the Indian Ocean. I would say that
the dream gives advance warning and then as the
time approaches the usual headache signs come up.
There still are not enough instances for me to
know for sure yet. And like you said, sometimes
things change and then you have to adjust all over again. I seldom dream of people, mostly
numbers, names, maps and orbital views.